Members of the Hezbollah Brigades fly the flag during the assault on Amerli.

In the wake of an offensive to liberate the central Iraqi town of Amerli from the Islamic State last summer, Shiite militias raided 30 villages in the surrounding area in reprisal attacks against Sunnis. The militias looted, burned thousands of buildings, and abducted at least 11 people, according to Human Rights Watch. The US military provided air support to Iraqi forces and the Iranian-backed Shiite militas during the initial fighting against the Islamic State in Amerli.

“After US air strikes and Iraqi fighters broke the siege [of Amerli], pro-government militias began to raid Sunni and mixed Sunni villages in the areas surrounding Amerli,” HRW stated in a report, titled After Liberation Came Destruction, which was released today.

“They [Shiite militias] raided and looted residential and commercial properties, later burning down or blowing up thousands of buildings in more than 30 villages” in Salahaddin province, the reported continued.

HRW was able to confirm that at least 3,200 building were torched during the “militias’ campaign of destruction” after Amerli was liberated on Sept. 1, 2014. The militias looted and burned or bombed buildings in September and “through the months of October, November and possibly December.”

“The widespread burning of civilian homes by the militia groups in areas under their control appeared to have had no clear military objective and to represent collective punishment against residents of local Sunni villages,” HRW stated.

The militias that were involved in the fighting in Amerli included Kata’ib Hezbollah (Hezbollah Brigades), Asiab al Haq (League of the Righteous), Saraya Khorasani (Khorasan Brigades), and the Badr Organization. Each of these militias, which operate under the aegis of the Popular Mobilization Committee, or Hashid Shaabi, are closely tied to Qassem Soleimani, the commander of the Qods Force, the external operations wing of the Iranian Revolutionary Guards Corps.

Shiite militia commanders have threatened to retaliate against Sunnis, who are seen as supporting the Sunni Islamic State, immediately after the liberation of Amerli.

“There is no way back for them [the Sunnis]: we will raze their homes to the ground,” a Hezbollah Brigades commander in Amerli who is known as Abu Abdullah told Reuters in mid-September 2014. In that same report, Kurdish fighters were quoted as calling Hezbollah Brigades the “Shiite Islamic State” and said that hostilities between Kurdish forces and the Shiite group is likely.

Despite the involvement of the Iranian-backed Shiite militias in Amerli, the US military launched four airstrikes against the Islamic State on Aug. 31, 2014.

Shiite militias have since taken the lead in liberating Jurf al Sakhar south of Baghdad and in areas in Diyala and Salahaddin provinces, including the current offensive in Tikrit, where US military officials estimate they make up more than 80 percent of the fighting force. The US has provided air support in Jurf al Sakhar, but has since declined to support the militias in the ongoing Tikrit offensive.

Despite this, top US officials have said that Iran’s role in Iraq and its support of Shiite militias can have a positive outcome. On March 3, General Martin Dempsey, the Chairman of the Joint Chiefs of Staff, characterized the the Shiite militias’ and Iran’s efforts to retake Tikrit from the Islamic State as “a positive thing.”

“Frankly,” General Dempsey said, “it will only be a problem if it results in sectarianism.”

But as the Shiite militias’ activities in Amerli documented by HRW have demonstrated, the Iranian-backed groups are already practicing “sectarianism.”

The dominance of the militias on the battlefield and their sectarian reprisals may serve to radicalize Sunnis and push them into the arms of the Islamic State. Additionally, the military’s increasing reliance on the militias strengthens Iran’s influence in Iraq.

Militias involved in Amerli offensive are closely tied to Iran

The Popular Mobilization Committee, which was formed by Prime Minister Nouri al Maliki to combat the Islamic State after the Iraqi military collapsed during the summer of 2014, is led by Abu Mahdi al Muhandis, a former commander in the Badr Organization who was listed by the US government as Specially Designated Global Terrorist in July 2009. The US government described Muhandis, whose real name is Jamal Jaafar Mohammed, as “an advisor to Qassem Soleimani,” the commander of the Qods Force, the external operations wing of the Iranian Revolutionary Guards Corps (IRGC).

In addition to leading the Popular Mobilization Committee, Muhandis is also said to direct the operations of Kata’ib Imam Ali (Imam Ali Brigade), another Shiite militia supported by Iran, as well as command the Hezbollah Brigades. Shebl al Zaidi, a former commander in the Mahdi Army who has been photographed with Soleimani in the past, is the secretary-general of the Imam Ali Brigade, which is operating from Camp Speicher, a sprawling military base northwest of the city.

Hezbollah Brigades was designated by the US State Department as a terrorist organization in July 2009. In that designation, State described the militia as “a radical Shia Islamist group with an anti-Western establishment and jihadist ideology that has conducted attacks against Iraqi, US, and Coalition targets in Iraq.” State also reported that the militia receives funding, training, logistics, guidance, and material support from Qods Force.

Saraya Khorasani is also backed by Iran. The group was advised by Hamid Taqavi, an IRGC general who was killed by an Islamic State sniper late last year. Ali al Yasiri, the leader of Saraya Khorasani, said that Taqavi “was an expert at guerrilla war” and that “People looked at him as magical,” Reuters reported. The militia has also put up billboards praising Taqavi throughout Baghdad and published videos online to commemorate the Iranian general.

Bill Roggio is a Senior Fellow at the Foundation for Defense of Democracies and the Editor of The Long War Journal.